Decision making may take on different styles or combinations of styles - as in random, rule governed or goal oriented decision making. Theorising about how individuals make decisions is an important element in a number of sciences, especially those involving economics, psychology and design. Terms such as 'decision theory' and  'choice theory' attempt to encapsulate these ideas. In addition, group decision making takes on an added dimension with complex interactions between group members. Terms such as 'public choice theory' and 'community participation' try to encapsulate approaches to the study of group decision making.

The use of computers, artificial intelligence and decision support systems to aid human decision making adds a further dimension to study of decision making. This dimension depends on merger of cognitive science, computer science and information and communication technology.  

Random Decision Making
Tossing a coin, rolling a dice or drawing straws may decide an issue. The decision maker requires no historical knowledge or memory of past events in order to take a new direction. This kind of 'decision' involves no learning through previous mistakes and can be automated so as not to involve humans through computers or other machines. 

Decision Making Based on Rules
Rule governed decisions presume that some people will make rules and some people will follow rules. The making of rules requires a process of description followed by a process of communication. The idea of a 'rule of law' is often seen as fundamental to the organisation of a democratic society. 

Economic Rationalism
'Economic rationalism' is a vogue term used to describe a raft of economic policies. These policies seek to use markets wherever possible to achieve an allocation of resources within society. (Lectures 3 and 4 show that constraints on what is possible in technical, economic and political terms can limit the institutional requirements for operation of markets.)

The World Bank, an agency of the United Nations, maintains a database of World Development Indicators comprising some 800 indicators organised into sections named as follows World View, People, Environment, Economy, States and Markets.

Advantage from Specialisation in Knowledge and Skills
The following table shows the basic idea behind trading to mutual advantage where person A or person B can erect one building in five person/days. However, by concentrating on tasks where each has an advantage over the other, they can erect one building in four person/days. 

The advantage in working together is offset to some extent by the costs of coordinating the activity of separate individuals. The economic rationale for organising occurs when the benefits of organised activity outweigh the cost of organisation.

The Origin of Towns and Urbanisation
Agriculture imposed a need for territorial defence as well as local law and order if the hard work of growing crops was not to be lost to raiding parties. Moreover specialisation in food production accompanied the growth of towns where walled cities provided a fall back defensive position as well as a centre for ancient arts and crafts. This urban/rural interaction created a role for transportation that persists with modern urbanisation. The need for  secure passage in transporting goods and services and territorial defence imposed high transport costs. Clark argues that people facing high transport costs:

Infrastructure, Mutual Defence and Social Organisation
The birth of ancient civilisation contrasted with an uncivilised world of barbarian raiders. Moreover, parts of the ancient world depended on extensive public works for irrigation and public roads as part of their agricultural enterprise. Territorial defence and physical infrastructure depended on development of more complex form of institutional infrastructure and taxation. This led to innovations such as development of writing, alphabets, calendars, numbering systems, arithmetic, geometry, measurement and written records for use in public administration, taxation and construction of physical infrastructure.

Urbanisation also led to development of a class structure comprising rulers, bureaucrats and scribes, artisans, soldiers and farmers. Hunter-gatherers generally lived well within the carrying capacities of their ranges and placed little pressure on available resources. The shift from hunter-gatherers to cropping involved greater agricultural product per unit area of land and per unit of labour but it came at a greater cost in vulnerability to pestilence and famine. 

Rise and Fall of Civilisations
Evidence from archaeology and history indicates the rise and fall of many civilisations over time. The rise and fall of the Roman Empire is a well known example in Western tradition. Increasing activity from barbarian raiders saw the collapse of centralised administration, decline in town life and resort to feudal arrangements over much of Europe through the Middle Ages. Feudal arrangements saw organisation for ordinary people centred on fortifications provided by castles to provide physical security and provision of local organisation by land lords. Regional defence depended on a coalition of forces organised in the name of a king. The king's right to rule was strongly supported by religious authority through religious teaching and oaths of coronation.

The Renaissance, Reformation and Enlightenment
New forms of social organisation became necessary for territorial defence with the development of gunpowder and cannon that could breach castle walls. About the same time, a new revolution in thinking was being made possible with the invention of printing based on movable metal type. The commercial interests of printers was for a growing literacy, but this growing literacy became a threat in time to established religious authority in the Reformation.

The growth of literacy together with significant geographical discoveries beginning with exploits of Portuguese and Spanish adventurers in the late fifteenth century led to new intellectual endeavours that would further challenge various views of the world held by religious authorities. The thirst for knowledge and several important intellectual discoveries in physics and chemistry gave further impetus to social change during the period known as the Enlightenment.

The Industrial Revolution
The Enlightenment provided an ethos for twin revolutions in politics and the production of goods and services. A model for political revolution began in England with its Civil War and Republic (1648-1660) and the 'Glorious Revolution of 1688. The American Revolution followed with its declaration of Independence in 1777. A French Revolution followed in 1789. A spate of revolutionary activity continued in Europe through the 1800s, culminating in the Russian Revolution in 1917.

These revolutionary changes in political power accompanied changes in class structure with a shift in vested interests. This shift was generally away from owners of land - a landed aristocracy - to owners in capital used in new manufacturing processes - a middle class or bourgeoisie. These shifts also had major impacts on landscape with centralisation of production in factories and rapid urbanisation to accommodate a workforce.

The Present Day
Urbanisation remains a major development issue as manufacturing production continues to emerge in developing countries. In developed countries, manpower requirements tend to reduce with increasing automation in industry. Emerging issues occur with rising relative prices in personal services that do not readily allow automation - especially in provision of health and education services and more so in rural areas.

Specialisation leads to a variety of outputs and variety is said to be 'the spice of life'. However, variety leads to complexity in government to regulate physical and institutional innovations. Commerce depends on information and knowledge about production techniques, products and prices.

New issues emerge because people may be disinclined to conduct some kinds of enquiry other than in face-to-face communication, especially when there is a need to establish trust in negotiations. This raises the question of whether there is an effective trade-off between the costs of telecommunications and the costs of transportation.